Visualz 3.0.1

First hotfix after the v3 launch. Tightens the AI pipeline and the web API surface that the desktop and brochure both consume.

Fixes

• AI jobs — added result_json persistence so completed generations survive a refresh and replay cleanly from history.
• Sessions — new server-side session helpers; sign-in / sign-up flows hardened against stale tokens.
• Web API client — large refactor of web/lib/api.ts for typed responses, retry behavior, and clearer error surfaces.
• Desktop perform component fix for an off-by-one on slot focus after canvas drop.